This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-213995, filed Jul. 28, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to a substrate processing apparatus and a substrate processing method each for performing, for example, heat processing and cooling processing for a substrate such as a semiconductor wafer or the like.
In processes of semiconductor device fabrication, a layer insulating film is formed, for example, by an SOD (Spin on Dielectric) system. In this SOD system, a wafer is coated with a coating film by spinning the wafer, and chemical processing, heat processing, or the like is performed for the wafer by, for example, a sol-gel process to thereby form a layer insulating film thereon.
When a layer insulating film is formed by the sol-gel process, for example, first an insulating film material, for example, a solution in which colloids of TEOS (tetraethoxysilane) are dispersed in an organic solvent is supplied onto a semiconductor wafer (hereinafter referred to as xe2x80x9cwaferxe2x80x9d). Thereafter, the wafer to which the solution is supplied is subjected to gelling processing, and then exchange of solvents is performed. Subsequently, the wafer on which solvents are exchanged undergoes heat processing.
In a series of these processes, various heat processing and cooling processing are performed. Commonly in the heating process, a wafer is carried into a heat processing chamber and the inside of the processing chamber is brought to a low-oxygen atmosphere while the wafer is supported by supporting members. After the low-oxygen atmosphere is reached, the wafer is mounted on a hot plate and subjected to heat processing. When the wafer is subjected to the heat processing at a high temperature, the processing is performed in a low-oxygen atmosphere to prevent oxidation of a coating film made of an insulating film material. Such a low-oxygen atmosphere is generally made by exchanging the inside of the processing chamber for N2 gas that is an inert gas. Further, in the cooling process, a wafer is mounted on a chill plate in a processing chamber and subjected to cooling processing while the inside of the processing chamber is brought to a low-oxygen atmosphere so that an inert gas is sent from a jet port disposed at a top portion of the processing chamber toward the front face of the wafer.
However, since the wafer is mounted on the hot plate and subjected to the heat processing after the processing chamber is brought to a low-oxygen atmosphere as described above, there is a disadvantage that the formation of a desired low-oxygen atmosphere requires considerable time, and the time required for heat processing under a low oxygen is virtually lengthened, thereby exerting a bad influence on a total processing time to form an insulating film to be formed on the wafer. Further, since the heating is performed by the hot plate, there is a disadvantage that the heat processing can not be uniformly performed for the entire face of a wafer, whereby heating unevenness occurs.
Furthermore, there is a disadvantage that in the cooling processing, the inert gas which is supplied toward the front face of the wafer becomes uneven within the surface, whereby cooling unevenness within the wafer surface occurs.
An object of the present invention is to provide a substrate processing apparatus and a substrate processing method capable of performing a heating process without heating unevenness in a short period of time.
Another object of the present invention is to provide a substrate processing apparatus and a substrate processing method without cooling unevenness.
To solve the aforesaid disadvantages, a substrate processing apparatus of the present invention comprises: a hot plate on which the substrate is mounted; an ascendable and descendable supporting member penetrating the hot plate for protruding from a front face of the hot plate to support the substrate in a state where the supporting member is raised and for retracting into the front face of the hot plate to mount the substrate on the hot plate in a state where the supporting member is lowered; a processing chamber having an ascendable and descendable shutter member disposed to surround the outer periphery of the substrate and provided with a plurality of blast ports along a thickness direction of the substrate mounted on the hot plate, the shutter member forming processing space between the shutter member and the hot plate in a state where the shutter member is raised or lowered; and inert gas supply means for supplying a heated inert gas into the processing chamber via the blast ports.
In the present invention, the plurality of blast ports are provided in the shutter member along the thickness direction of the substrate, so that the heated inert gas to be supplied via the blast ports is sent to both faces of the substrate in a state where the substrate is supported by the supporting member.
Accordingly, both the faces of the substrate can be heated at the same time, whereby the substrate is uniformly heated within the surface and heating unevenness never occurs. Further, because heating of the substrate can be performed by the inert gas during the interval from when the substrate is supported by the supporting member to when it is mounted on the hot plate, the time required for the heat processing can be shortened compared with the case where conventionally the heat processing is performed by the hot plate after the low-oxygen atmosphere is prepared. Furthermore, the inert gas is supplied to both the faces of the substrate in a direction almost horizontal to the substrate, whereby the inert gas also has a function of separating oxygen remaining in the processing chamber from the substrate, so that oxidation of the coating film formed on the substrate never proceeds even in a heating state.
An embodiment of the present invention is characterized in that the substrate supported by the supporting member is positioned at a position to which the substrate is delivered from the outside of the apparatus and near a midpoint of vertically placed blast ports in a state where the shutter member is raised or lowered to form the processing space between the shutter member and the hot plate. According to the above configuration, the inert gas to be sent from the blast ports can be supplied to both the faces of the substrate, whereby heating unevenness never occurs.
An embodiment of the present invention is characterized in that the supporting member to which the substrate is delivered from the outside of the apparatus is lowered to mount the substrate on the hot plate in a state where the shutter member is raised or lowered to form the processing space between the shutter member and the hot plate and the heated inert gas is supplied from the blast ports. According to the above configuration, a supply process of the inert gas and a heating process can be performed at the same time during the interval of the movement of the substrate from when the substrate is supported by the supporting member to when it is mounted on the hot plate, whereby the time required for the heat processing can be shortened compared with the case where conventionally the heat processing is performed by the hot plate after the low-oxygen atmosphere is prepared.
An embodiment of the present invention is characterized in that the inert gas supply means exchanges the inside of the processing chamber for the inert gas by supplying the inert gas with gradually increasing the supply amount thereof. According to the above configuration, the supply amount of the inert gas is gradually increased, whereby the temperature can be efficiently raised while oxidation of the coating film formed on the substrate is prevented and the heat processing time can be shortened compared with the conventional art. In other words, oxidation tends to proceed with increasing temperature in the coating film formed on the substrate, but it is possible to decrease the oxygen concentration in the processing chamber with increasing temperature to a high temperature state in the configuration of the present invention, so that efficient heat processing can be realized while oxidation of the coating film is prevented.
A substrate processing apparatus of the present invention comprises: a chill plate on which the substrate is mounted; a processing chamber in which processing space for processing the substrate is formed between the processing chamber and the chill plate; inert gas supply means for supplying a cooled inert gas; and an inert gas jet nozzle provided above almost the center of the substrate mounted on the chill plate and having a jet port for slantingly jetting the inert gas supplied from the inert gas supply means toward the outer periphery of the substrate.
The present invention has the inert gas jet nozzle having the jet port for slantingly jetting the inert gas toward the outer periphery of the substrate, whereby the inert gas can be uniformly supplied to the entire face of the substrate, so that cooling unevenness never occurs within the substrate surface.
A substrate processing method of the present invention comprises the steps of: (a) carrying a substrate to a position above a hot plate; (b) lowering the substrate while a heated inert gas is supplied from the outer periphery side of the substrate to both faces of the substrate; and (c) heating the substrate while the substrate is mounted on the hot plate.
In the present invention, the heated inert gas is supplied to both the faces of the substrate, whereby the entire face of the substrate can be heated without unevenness.
An embodiment of the present invention is characterized in that the heat inert gas is supplied with the supply amount thereof gradually increased in the step (b). According to the configuration, the temperature can be efficiently raised while oxidation of the coating film formed on the substrate is prevented and the heat processing time can be shortened compared with the conventional art.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.